Elastic-fluid turbine



Jan; 8, 1929.

J. HIDORAN ELASTIC FLUID TURBINE Filed June 21, 1925 ITWVGTWtOT 'Z John H. Do'rosn,

His Attorn gg Patented Jan. 8, 1929.

UNITED STATES PATENT OFFICE...

JOHN H. DORAN, OF SCI-IENECTADY, NEW YORK, ASSIG1\TOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ZELASTIC-FILFU'II) TURBINE.

Application filed June 21, 1926. Serial No. 117,293.

The present invention relates to elastic fluid turbines, and especially to rotors for such turbines.

At the low pressure end of a turbine rotor for a large machine, the buckets become quite long and it is well known in connection with bucket rows having buckets of considerable length to provide circuniferentially-extending tie wires between the inner and outer ends of the buckets to strengthen them and increase the stiffness of the buckets. It is desirable from the standpoint of strengthening the bucket row that such tie wires extend continuously around the wheel, that is, that they be in the. form of continuous unbroken rings.

However, generally they have been made in sections in order to avoid the stresses which would be setup in a continuous tie wire when the turbine is in operation. In this connec tion, it will be appreciated that when a turbine rotor is running, the buckets stretch in a radial direction due to centrifugal force, and this tends to increase the diameter. This means, if a tie wire is continuous, that it must stretch also so that in the case of an ordinary tie wire, if made continuous, stresses of an excessive value may be set up in it.

The object of my present invention is to provide an improved tie wire which may be continuous and which capable of stretching a limited amount without having stresses of an excessive value set up in it, and for a consideration of what I believe to be novel and my invention, attention is directed to the. accompanying description and the claims appended thereon.

In the drawing, Fig. 1 is a side view of a portion of a turbine rotor, the buckets of which are provided with-a tie wire embodying my invention, and Fig. 2 is a radial sectional. view.

Referring to the drawing, 1 indicates a turbine shaft, 2 a rotor thereon, 3 a row of buckets carried by the rotor, and 4: a sectional bucket cover for the buckets. Intermediate between their ends, the buckets are provided with tie wires 5 permanently fastened in notches 6 inthe edges of the buckets.

Now, according to my invention, I form the tie wire of one continuous piece and between buckets I provide enpansible bends or kinks in the tie wire, as is indicated at 7. By this arrangement, I provide a tie wire which is suiiiciently stiff between buckets to hold the buckets in a whoily satisfactory manner, but which at the same time is capable of straightening out slightly or stretching so as.

bucket ringand which avoid the difficulties met with heretofore in the use of continuous tie wires.

What I claim as new and desire to secure by Letters Patent of the United States is 1. The combination with a turbine rotor having a row of buckets, of a tie wire for the buckets, said tie wire being in one continuous piece secured to the buckets and having kinks along its length which lie between the buckets and are expansible to permit the wire to be stretched. I

2. The combination with a turbine rotor having an annular row of buckets, of a tie wire for the bu ckcts in the form of a continuous ring permanently fastened in the edges of the buckets, the edges of the buckets being notched to receive the wire and said'wire having kinks along its length which lie between the buckets. s

3. The combination with a turbine rotor having a rowof buckets, of a tie wire extending along the row and secured to the buckets, said wire having expansible bends between the buckets which permit the wire to be stretched without setting up in it stresses of excessively high value.

In witness whereof, I have hereunto set' my hand this 19th day of June, 1926.

\ JOHN H. DORAN. 

